(1) Field of the Invention
This invention relates to processes for enhancing the dyeability and softness of crosslinked cellulosic fabrics.
(2) Description of the Prior Art
The application of crosslinking agents to cellulosic fabrics to improve smooth drying properties has the detrimental effect of reducing strength properties and reduces their affinity for dyes. Examples of some agents that are utilized to crosslink cellulose are dimethylol dihydroxyethylene (DMDHEU) and trimethylol acetylenediureine (GUR).
Modern textile practice requires that cellulosic fabric be dyed before finishing for smooth dry performance. These fabrics when crosslinked with readily available agents, are dye resistant. There are a few known methods which permit dyeing subsequent to crosslinking. Examples of such processes would include U.S. Pat. No. 3,788,804 (Harper et al.) which teaches the use of crosslinking agents and hydroxycarboxylic acids to form crosslinked fabrics with acidic grafts and dyeing the fabric with basic dyes. Also, U.S. Pat. No. 3,807,946 (Harper et al.) teaches the use of crosslinking agents and a reactive additive such as triethanolamine to form a crosslinked fabric with a grafted amine and dyeing with an acid dye.
U.S. Pat. No. 3,853,459 (Harper et al.) Utilizes a treatment of cross-linking agent and polymer to form a durable-press fabric with a polymeric treatment and dyeing with a disperse dyestuff. These patents teach in common dyeing modified cellulosic fabrics with non-cellulosic dyestuffs. Consequently, the performance of these dyes on a cellulosic substrate is not as good as cellulose dyed with normal dyestuffs such as direct or reactive dyes which are usually used on cellulosic fabrics.
Also many millions of pounds of softeners and builders are utilized in laundry fabrics to give such laundered fabrics an acceptable and soft hand. Such materials are added during laundering, but permanent binding of these agents would confer durable properties to cellulosic fabric.